NRZ and biphase-L formatted quadriphase modulated GPS transmission method
AssigneeThe Aerospace Corporation
InventorsSrinivasa H. Raghavan, Jack K. Holmes
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Abstract
An NRZ and biphase-L formatted, quadriphase modulated GPS signal transmission communication method provides for the simultaneous modulation of two CDMA spread spectrum codes such as the GPS C/A code and either the P(Y) code, or an arbitrary NEW code modulating a single carrier for GPS use in one or both L1 and L2 bands. The use of NRZ formatting and biphase-L formatting provides spectral separation even though both spread spectrum signals are modulated onto the same carrier.
Claims8
A transmission method for spectral separation of a first and a second modulated spread spectrum signals transmitted over a bandwidth having center carrier frequency, the method comprising the steps of,
- first code generating a first code signal,
- first code NRZ formatting the first code signal,
- first data generating the first data,
- first data NRZ formatting the first data,
- first providing a spread spectrum signal from the NRZ formatted first code signal and the NRZ formatted first data,
- second code generating a second code signal,
- second code biphase-L formatting the second code signal,
- second data generating a second data,
- second data NRZ formatting the second data,
- second providing a second spread spectrum signal from the biphase-L formatted second signal and the NRZ formatted second data,
- providing first and second modulated spread spectrum signals from the first and second spread spectrum signals in quadrature at the center carrier frequency within the bandwidth, and
- broadcasting the first and second modulated spread spectrum signals within the bandwidth at the center carrier frequency, the second modulated spread spectrum signal has a spectral null at a spectral maximum of the first modulated spread spectrum signal at the center carrier frequency providing spectral separation of the first and second modulated spread spectrum signals.
A communication method for transmitting and receiving a first and a second modulated spread spectrum signals within a bandwidth having center carrier frequency, the method comprising the steps of,
- first code generating a first code signal,
- first code NRZ formatting the first code signal,
- first data generating a first data,
- first data NRZ formatting the first data,
- first providing a spread spectrum signal from the NRZ formatted first code signal and the NRZ formatted first data,
- second code generating a second code signal,
- second code biphase-L formatting the second code signal,
- second data generating a second data,
- second data NRZ formatting the second data,
- second providing a second spread spectrum signal from the biphase-L formatted second signal and the NRZ formatted second data,
- providing first and second modulated spread spectrum signals from the first and second spread spectrum signals in quadrature at the center carrier frequency within the bandwidth, and
- broadcasting the first and second modulated spread spectrum signals within the bandwidth at the center carrier frequency, the second modulated spread spectrum signal has a spectral null at a spectral maximum of the first modulated spread spectrum signal at the center carrier frequency providing spectral separation of the first and second modulated spread spectrum signals,
- receiving the modulated first and second modulated spread spectrum signals over the bandwidth at the center carrier frequency,
- providing a first despread modulated signal from the first modulated spread spectrum signal,
- providing a second despread modulated signal from the second modulated spread spectrum signal,
- providing a first demodulated signal from the first despread modulated signal,
- providing a second demodulated signal from the second despread modulated signal,
- providing the first data from first demodulated signal, and
- providing the second data from the second modulated signals.
Dependencies are inferred from the claim text.